Universal sound-transmitting means.



P. J. HACKETT.

UNIVERSAL SOUND TRANSMITTING MEANS.

APPLICATION FILED OCT. 4, I913.

1. 14 92%. Patented Aug. 10,1915.

TE STS FATNT TTFFTQQ PAUL J. HACKIETT, 0F SEATTLE, WASHINGTON, ASSIGNOR T0 UNIVERSAL HIGH EOWER TELEPHONE COMPANY, OF KING COUNTY, WASHINGTON.

UNIVERSAL SOUND-TRANSMITTING MEAN S.

" Specification of Letters Patent.

Patented Aug, 1d, 1915.

To all whom it may concern:

Be it known thatfl, PAUL J. Haoknrr, a

citizen of the United States, and a resident of Seattle, in the county of King, State of Washington, have invented certain new and useful Improvements in Universal Sound- Transmitting Means, of which the following is the specification.

This invention relates to sound transmitting means and more particularly to that class of-s'uch devices in which a plurality of stationary electrodes are associated with a plurality of movable ones, and in which the resistance to the electrical currentis varied at difi'erent points.

The principal object of my invention is to provide a device of this character in the operation of which no appreciable waste of the current occurs at any time, to the end that the sound waves of the voice as they enter the sending end of the telephone system aretransmitted .to the receiving end thereof with a minimum of loss.

T am aware that different forms of differential transmitters are already known in the art, but-in such forms, so far as I am aware, a considerable portion of the electric current is not used.

An important feature of my invention is the peculiar and compact manner of construction of the transmitter, taken as a whole and which results in ease of assembling of the parts.

Other features and objects will appear as the invention is more fully described in the following specification, illustrated in the accompanymg drawings and pointed out in the appended claims.

In the drawings, Figure 1 is a side elevation of my device, partly broken away, and partly in central vertical section. Fig. 2 is an enlarged detail view of one of the wiring connections. Fig. 3 is a top plan view of the device, partly 1n section upon the line y 1 of Fig. 1. Fig. 4 is an enlarged fragmentary detail view of one of the resistance chambers and its adjacent parts.

Referring now more particularly to the drawings, reference numeral 1 designates'a tubular sound passage whichis threaded, as shown in Fig. 1, so that the correspondingly threaded end of the mouth piece 2 may be secured to it. Extending radially from the said passage 1 are the similar passages 3, 4, 5, and 6 respectively, all of the said passages communicating with each other as plainly seen in Figs. 1 and 3. These sound passages may each be separate tubes and all of the said tubes joined together in any suitable manner, or a five-way casting may be employed and afterward bored out and machined, as will be understood. As sound waves are set up within the mouth piece 2 and the passage 1, due to the human voice or to other causes, the said waves are deflected equally into the passages 3, a, 5, and 6,-by reason of the pyramid 7 whose apex is coincident with the vertical plane of the longitudinal axis of the tube 1, and the four corners of whose base lie just within the vertical plane of the interior walls of the said tube. The pyramid 7 is, in this 111 stance, secured to the inner walls of the" sound passages a and 5 by means of the ma-- chine screw 8 which passes through the depressed portion 9 and also through a fiber disk 10, said depressed portion being square to exactly conform to the base of pyramid 7, so that the same will not become displaced from its described position.

The outer ends of the tubes 3, 4:, 5, and 6 respectively are threaded, as shown, and upon the outer end of each of the said tubes a correspondingly threaded disk 11 is seecured to which is in turn suitably secured, any approved manner, a circular cap 12 in which may be the ventilating holes 13. The top of the said cap is centrally bored and threaded to receive the correspondingly threaded bushing 14, the inner end of which projects slightly into the cap 12, and has screw threaded to it the cap 15, between which and the circular edge of the said bushing is confined a fixed electrode 16. The other end of the said bushing has secured to it a similarcap 15 and the second fixed electrode 16 By means of the screws 17, or other suitable means, a disk 18 is secured to the top of the cap 12, the said disk and cap, however,being held in spaced relation to each other by means of the insulating washers 19 and the circular edge of the diaphragm 20 which lies between the said washers. By means of the slender steel rod 21 and the small nuts 22, an electrode 23 is secured to each side of the diaphragm 20, there being a very thin metallic conducting strip 24 upon each side of the said diaphragm and confined between the same and one of the electrodes 23, and the said str ps are joined together at 25 so as to form a single electrical conductor 26. The inner face of the cap 12 may be annularly recessed to receive the rubber or other resilient insulating rings 27, and which allows the circular strip 24 upon each side of the said diaphragm 28 which is confined between the said rings, protected by the rim or flange 29 of the cap 12. The rod 21 slidably passes through the aperture 31 in the cap 15 and electrode 16 and the similar aperture 32 of the stufling box 33, so that both the diaphragms 20 and 28 vibrate in unison. The disk 18 and the cap 12 may be annularly recessed to receive the asbestos or other like material indicated at 34.

From the foregoing it will be seen that the chamber formed by the electrodes 16 and 16 and the circular walls of the bushing M is subdivided into two sub-chambers which are at each side of the diaphragm 20 and each of the sub-chambers is filled with granular carbon or other like material indicated at 35.

36 indicates a dynamo or other suitable source of direct current which is electrically connected by means of the conductors 26 and the thin conducting strips 24, to each of the movable electrodes 23. The disk 18 at the left (see Fig. l) is connected to the disk 18 which is oppositely disposed to it by means of the wire 37 and the corresponding oppositely disposed caps 12 are connected by means of the wire 38 and similar -wire connections extend between said plats and caps which are at the respective outer ends of the sound tubes 4: and 6 (see Fig. 3).

39 and 40 indicate induction coils the primary windings of which are connected in circuit to the respective wires 38 and 37, and 41 indicates co-acting secondary coils in the wire 42, each end of which wire is adapted to be connected to the receiving end of a telephone system.

It will be understood that while I have re ferred to the caps 12 and their associated parts as being arranged in oppositely disposed pairs, that particular arrangement is not imperative.

The operation of the device is as follows :When sound waves are set up within the mouth piece 2 they travel downwardly as seen in Fig. 1 and are deflected equally to each of the four sound tubes 3, 4, 5, and 6 by means of the corresponding sides of the pyramid 7, whence they travel to the respective diaphragms 28 and simultane ously impinge thereagainst, causing them and their connected diaphragms 20 to swell outwardly, which causes the carbon granules which are between the fixed electrodes 16 and the movable electrodes 23 to cohere in greater degree than when the said diaphragms were at rest, and at the same time causes the granules on the opposite of the nmaeva respective movable carbons to cohere in less degree with the result that the electrical current which had previously been equally divided in its flow through the course outlined, to diverge unequally, the greater portion thereof taking the course of least resistance through the granules which have just been pressed together by the said movement of the diaphragms, thence the current flows through the cap 12, through the wire 37, into the oppositely disposed cap 12, through the outer chamber on that side which contains the compressed granules, the movable electrode 23 on that side, and finally returns to the dynamo through the outer thin metal strip 2 1 and metallic connection 26. While the main current has taken the path of least resistance, as just traced, a small portion thereof has at the same time passed along through the more loosely associated carbon granules on the inner side of the movable electrodes, thence through the adjacent cap 12, on one side of the device, the wire 38 to the corresponding cap on the other side of the device, through the more loosely associated granules on the inner side of the movable electrode 23, through the inner movable electrode 23, the inner thin metallic conductor 24, and finally back to the dynamo through the conductor 26 on that side. In other words the sound Waves which entered the mouthpiece 2 have, through the means described, caused the electric current first traced to be increased, and the current last traced to be correspondingly and simultaneously decreased, and it is obvious that a reverse movement of said diaphragms will cause a reversal of the conditions just described. The result of this is that the current is induced in both the secondary coils 41, and I thus avail myself at all times of the fulleffect of both the falling current as Well as the rising current in the respective wires 37 and 38 when the diaphragms are actuated.

While I have shown a particular form of embodiment of my invention, I am aware that'many changes in the details of the construction thereof will readily suggest themselves to others skilled in the art, without departing from the spirit and scope of the invention, and I desire to avoid being limited to the exact form shown and described.

What I claim is 1. In a sound transmitting device, the combination with the main sound receiving passage of a set of sound passages which are intercommunicating and which communicate with the said main passage and diverge therefrom, a sound deflector having as many straight deflecting sides as there are passages in the said set and positioned so that the sound from said main passage is equally deflected to each of the passages in the said set.

2. In a sound transmitting device, the combination with the main sound receiving passage of a plurality of other sound passages which are intercommunicating and communicate with the said main passage and diverge radially and at right angles to the said main passage, and having a recess in that portion of the common bottom of said plurality of passages, a sound deflecting member having straight sides equal incombination of a five-Way hollow casting four of which ways diverge in a common horizontal plane from a common center and one of which diverges vertically from that center at a right angle to said plane, said four ways being angularly recessed at their common center, a pyramid whose base snugly fits into the said recess and Whose sides deflect the sound from the said vertical way equally into the other ways.

Done at Seattle, \Vashington, this 22nd day of September, 1913.

PAUL J. HACKETT.

Witnesses:

FRED. P. Gonm, R. D. SMALLEY.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

